In the illustrious history of Manchester United, few captains have performed to the standard that Roy Keane did.
Under the leadership of Sir Alex Ferguson, the Irish midfielder was devastatingly brilliant, enforcing the midfield in such a manner that every other attack-minded player could pretty much do what they liked.
Without the former Nottingham Forest man, United's ridiculous trophy haul in the 1990's and 2000's would probably not have been as fruitful.
Keane's performance in the 3-2 victory over Juventus in Turin during their Champions League winning season in 1999 will always be remembered as one of the great virtuoso performances.
However, in 2005, the often controversial Irishman was sold to Celtic after acrimoniously departing Old Trafford.
It is known that he had a bit of a falling out with Ferguson, but the actual details surrounding the feud are still relatively unknown.
Now, a key piece of information has been revealed by Alastair Campbell in the Sunday Times as he states there was one thing that provoked Ferguson into offloading his leader.
In September 2006, almost a year after Ferguson and Keane had parted ways, Campbell writes that ‘he [Ferguson] felt he had what it took in so many ways but he had demons and they would come out,’ reports the Sunday Times, per Manchester Evening News.
"He was actually someone who didn’t like people that much unless they met his own standards.’
Campbell had expressed his surprise to Ferguson about his decision to let Keane go: “I said you used to say he was the most intelligent player you’d had, and the one likeliest to be a top manager.
"He went ‘Wrong. There is something not right there’."
So, it turns out Keane's hot-headed attitude on the pitch lead to his demise in the dressing room at United.
The Irishman has gone on to manage several high-profile English sides, including Ipswich and Sunderland.
However, he has never really proved himself as a boss and perhaps Ferguson's reasoning back in 2006 is the reason.
Keane is now Martin O'Neill's assistant with the Irish national team and the duo have endured a fairly indifferent spell, with qualification for the 2018 World Cup almost unattainable.
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